Funding for this research was provided by:
National Natural Science Foundation of China (Grant No. 81571638)
Text and Data Mining valid from 2020-01-06
Received: 1 August 2019
Accepted: 5 December 2019
First Online: 6 January 2020
Ethics approval and consent to participate
: The Ethics Committee of West China Hospital of Sichuan University approved this study, and informed consent was obtained from each participant.
: Not applicable.
: The authors declare that they have no competing interests.